1. Field of the Invention
The invention relates to land vehicles, bodies and tops. More specifically, the invention is a folding air deflector for use on an automobile or truck pulling a trailer or similar large load.
2. Description of the Prior Art
Vehicle air deflectors are commonly used to improve gas mileage by reducing drag against a towed trailer. The purpose of the deflector is to direct air currents over the top of the trailer, thus avoiding direct impingement of the air currents against a vertical wall of the trailer.
Applicant is the inventor of a deflector shown in U.S. Design Patent No. 241,531 of which the present invention is an improvement. That deflector, like many others in the art, is attached to the roof of a vehicle for multi-point support against the constant pressure and vibration caused by wind currents. A properly mounted, firmly supported deflector of the configuration shown in the above design patent has been found to increase gasoline mileage by over eighteen percent.
One problem in the use of air deflectors is that the towing vehicle may at times operate without having a trailer attached thereto. In this instance, the deflector is no longer serving a useful purpose and, in contrast, may increase wind resistance against the vehicle, resulting in decreased gasoline economy. It is therefore important that means be provided to remove the deflector from the wind stream. The obvious expedient of removing the deflector from the vehicle is, in practice, unsuitable, as the size of the deflector is often greater than the vehicle width, making it impossible to store the deflector within the vehicle. Further, the mounting of the deflector on the vehicle may be permanent to avoid vibration when the vehicle is travelling at high speed.
Some deflectors are foldable for removal from the wind stream. U.S. Pat. No. 3,822,910 teaches a deflector that can be folded forward by unbolting portions of the associated support frame. U.S. Pat. No. 3,596,974 teaches a deflector that can be pivoted into a horizontal position by merely loosening wing nuts on pivot bolts that hold the deflector at any angle. Both of these deflectors maintain their original size when in folded position and may be strongly acted upon by cross winds or updrafts even when folded out of direct wind currents. Furthermore, the deflector of the latter patent lacks support necessary to prevent damaging vibration when in deployed position. It is therefore desirable to create a deflector that is firmly supported in both deployed and folded positions, and that presents a reduced size to the wind when the deflector is folded. In addition, it is desireable for a deflector to be uniquely supported so that wind currents assist in maintaining the deflector in deployed position, and so that the deflector can be folded in a matter of seconds without tools.
The present invention attempts to remedy the above noted problems of the prior art while achieving the stated desirable goals.